The invention concerns an activating pin for a valve connector for connecting to inflation valves, the connector comprising a housing to be connected to a pressure source, within the housing a coupling hole having a central axis and an inner diameter approximately corresponding to the outer diameter of the inflation valve to which the valve connector is to be connected, and a cylinder and means for conducting gaseous media between the cylinder and the pressure source, and which activating pin is arranged for engaging with a central spring-force operated core pin of the inflation valve, is arranged to be situated within the housing in continuation of the coupling hole coaxially with the central axis thereof and comprises a piston part with a piston, which piston is to be positioned in the cylinder movably between a first piston position and a second piston position.
It is well-known from PCT/DK96/00055, now U.S. patent application Ser. No. 08/837,505, herein incorporated by reference, that an activating pin located within the coupling house can be designed as a piston equipped with a suitable seal and a piston rod that is slidable in the cylinder-shaped coupling house. The piston can be held in a longitudinal position against the cylinder valve without applying physical force so that the piston automatically slides, after the valve connector is placed on the inflation valve, by means of compressed air. This compressed air comes from the pressure source such that the piston, in the proximal position to the valve, (1) opens up the inner valve, (2) opens the air passage to the valve and, (3) tightens less than 100% against the cylinder wall while in the distal position from the valve.
FIG. 14 in PCT/DK96/00055 shows a valve (360) which must be closed against the piston control. The disadvantage is that the above-mentioned two seals must be operational at a certain section of the sliding. This requires very accurate calibration of the cylinder wall and the piston movement. Furthermore, the piston has a precisely defined opening zone and can thus only adjust itself to a minor extent to the tolerances of the pump valve in question.
FIGS. 8, 9, 10, 14, and 15 in PCT/DK96/00055 show various activating pins equipped with a center blind drilling or a center drilling, side drillings and a V-shaped milling at the bottom which is perpendicular to the center axial drilling of the piston. The effect of this is that more force than necessary has to be applied when pumping, especially at high air velocities.
FIG. 9 in PCT/DK96/00055 shows an activating pin which has a center drilling, side drillings and a V-shaped milling at the bottom. When the coupling is connected to e.g. a high pressure pump with a built-in check valve, the spring keeps the valve of the activating pin in a closed position after uncoupling of a Schrader valve. If a tire with a Sclaverand valve has to be pumped immediately afterwards, one has to apply a large force to slide the activating pin which opens the inner valve of the Sclaverand valve. Air will escape and consequently the pumping time will be substantially longer if the tire has already been partly pumped. This last-mentioned problem also exists in the embodiments shown in FIGS. 10 and 15 in PCT/DK96/00055.
The purpose of the present invention is to produce a reliable activating pin which is: (1) inexpensive, (2) has low aerodynamic drag making it comfortable to use for pumping purposes, and (3) provides the shortest possible pumping time.
These tasks are solved by the invention where the activating pin further comprises a valve part, the piston part comprises within it a channel, the cross-section of said channel is, at least one part of said piston part, consisting of sectors, wherein in each sector the distance between the center point of the channel cross-section and the outermost limiting surface of the channel is larger than the corresponding distance measured along the line separating the sector from an adjacent sector, and said valve part is positioned movably with respect to said piston part between a first valve position and a second valve position for enabling the conduction of gaseous and/or liquid media through said channel when said valve part is in said first valve position, and inhibiting the conduction of gaseous and/or liquid media through said channel when said valve part is in said second valve position.
The channels are positioned in a mainly longitudinal direction in relation to the center axis of the housing, and can be defined by at least one cross section which approximately can be defined by at least one curve. The curve is closed and can be defined by two unique modular parametrisation Fourier Series expansions, one for each co-ordinate function:             f      ⁡              (        x        )              =                            c          0                2            +                        ∑                      p            =            1                    ∞                ⁢                  xe2x80x83                ⁢                              c            p                    ⁢                      cos            ⁡                          (              px              )                                          +                        ∑                      p            =            1                    ∞                ⁢                  xe2x80x83                ⁢                              d            p                    ⁢                      sin            ⁡                          (              px              )                                            where            c      p        =                  2        π            ⁢                        ∫          0          π                ⁢                              f            ⁡                          (              x              )                                ⁢                      cos            ⁡                          (              px              )                                ⁢                      xe2x80x83                    ⁢                      ⅆ            x                                          d      p        =                  2        π            ⁢                        ∫          0          π                ⁢                              f            ⁡                          (              x              )                                ⁢                      sin            ⁡                          (              px              )                                ⁢                      xe2x80x83                    ⁢                      ⅆ            x                              xe2x80x830xe2x89xa6xxe2x89xa62xcfx80,xxcex5R
pxe2x89xa70,pxcex5N
cp=cos-weighted average values of f(x),
dp=sin-weighted average values of f(x),
p=representing the order of trigonometrical fineness
thereby resulting in a large flow cross section area. All kinds of closed curves can be described with this formula, e.g. a C-curve. One characteristic of these curves is that when a line is drawn from the mathematical pole which lies in the section plane it will intersect the curve at least one time. A regular curve bounding a region which is symmetric with reference to at least one line which lies in the section plane through the mathematical pole can be defined by a single Fourier Series expansion:             f      ⁡              (        x        )              =                            c          0                2            +                        ∑                      p            =            1                    ∞                ⁢                  xe2x80x83                ⁢                              c            p                    ⁢                      cos            ⁡                          (              px              )                                            where            c      p        =                  2        π            ⁢                        ∫          0          π                ⁢                              f            ⁡                          (              x              )                                ⁢                      cos            ⁡                          (              px              )                                ⁢                      xe2x80x83                    ⁢                      ⅆ            x                              xe2x80x830xe2x89xa6xxe2x89xa62xcfx80,xxcex5R
pxe2x89xa70,pxcex5N
cp=weighted average values of f(x),
p=representing the order of trigonometrical fineness.
When a line is drawn from the mathematical pole it will always intersect the curve only one time. In order to minimize the aerodynamic friction the channels are positioned mainly parallel to the centerline of the activating pin.
When the curves are approximately defined by the following formula, the cross section area of the channels is optimized by a certain given cross section: e.g. a section which combines approximately laminar flow and which can guide a central piston valve rod. It is then also possible to obtain a contact area for a Schrader valve core. This means that a bridge is unnecessary. In the following description, curves defined by the formula have been given the name xe2x80x9cflower-shapedxe2x80x9d. The formula is:             f      ⁡              (        x        )              =                            c          0                2            +                        ∑                      p            =            1                    ∞                ⁢                  xe2x80x83                ⁢                              c            p                    ⁢                      cos            ⁡                          (                              3                ⁢                px                            )                                            where            f      ⁡              (        x        )              =                  r        0            +              a        ·                                                            sin                2                            ⁡                              (                                  n                  2                                )                                      ⁢            x                                2            ⁢            m                                          c      p        =                  6        π            ⁢                        ∫          0                      π            3                          ⁢                              f            ⁡                          (              x              )                                ⁢                      cos            ⁡                          (                              3                ⁢                px                            )                                ⁢                      xe2x80x83                    ⁢                      ⅆ            x                              xe2x80x830xe2x89xa6xxe2x89xa62xcfx80,xxcex5R
pxe2x89xa60,pxcex5N
cp=weighted average values of f(x),
p=representing the order of trigonometrical fineness
and where this cross-section in polar co-ordinates approximately is represented by the following formula:   r  =            r      0        +          a      ·                        "LeftBracketingBar"                      sin            ⁡                          (                                                n                  2                                ⁢                                  xe2x80x83                                ⁢                ϕ                            )                                "RightBracketingBar"                m            
where
r0xe2x89xa70,
axe2x89xa70,
mxe2x89xa70, mxcex5R,
nxe2x89xa70, nxcex5R,
0xe2x89xa6xcfx86xe2x89xa62xcfx80,
and where
r=the limit of the xe2x80x9cpetalsxe2x80x9d in the circular cross section of the activating pin,
r0=the radius of the circular cross section around the axis of the activating pin,
a=the scale factor for the length of the xe2x80x9cpetalsxe2x80x9d,
rmax=r0+a,
m=the parameter for definition of the xe2x80x9cpetalxe2x80x9d width,
n=the parameter for definition of the number of xe2x80x9cpetalsxe2x80x9d,
xcfx86=the angle which bounds the curve.
Pursuant to the invention, an activating pin ensures a large flow cross section which, by means of radial fins, also produces an approximately laminar flow which contributes to a reduced pressure drop during the flow. Similarly, the radial fins can control any centrally positioned valve without blocking the air passage.
In a first embodiment of the invention, the piston rod is equipped with two blind drillings parallel to the center axis that reaches the activating pin at both ends of the activating pin. The piston rod is also equipped with a concentric valve made of an elastic material, e.g. a valve rubber used on a Dunlop-Woods valve and squeezed onto the piston rod between e.g. its upper and lower part covering the radial drilling proximal to the pressure source. The radial drilling has an azimuth angle xe2x88x9d larger than or equal to 90xc2x0 to the center axis of the piston, seen in the flow direction of the air at flow from the side of the pressure source. Furthermore, the distal radial drilling has an azimuth angle xcex2 larger than or equal to 90xc2x0 to the distal center drilling of the piston, seen in the flow direction of the air at flow from the side of the pressure source. To ensure an interaction between the piston and the inner valve in a Schrader valve, the radius r0 in the distal blind drilling is smaller than the radius r0 of the proximal part of the center drilling. Due to evident arrangements in dimensioning the by-pass, the piston control is proximally equipped with longitudinal air ducts and/or having a bigger diameter. Moreover, the side of the piston is chamfered. If connected to e.g. a pump with a built-in check-valve, the connector needs to have an airing valve or a similar solution for providing the shortest pumping time. This results in a reliable activating pin because the pin valve works independently of the piston control fit and tolerances of the pump valves in question. It also results in a pin with low aerodynamic drag, which is comfortable for pumping purposes and which is inexpensive to produce.
A second embodiment is an improvement of the first embodiment where the coupling is connected to e.g. a high-pressure pump with a built-in non-return valve. A spring force being produced by means of the combination of compressed air and the valve lever passing through the piston in a eccentric position ensures the lowest possible pumping time. The effect of the eccentric valve lever is that the air pressure in the space between the non-return valve of the pump and the activating pin becomes equal to the pressure of the surroundings as the valve lever opens the above-mentioned space if a Schrader valve is disconnected. It is thus always possible to couple a Sclaverand valve without air escaping from the tire. Alternatively, an airing valve which is constantly shut could be established in the above-mentioned space when the connector is coupled to the valves or when the activating pin touches the core of the Schrader valve. This can take place if, for example, the airing is shaped as a narrow channel at the pressurized side of the activating pin relative to the distal end of it. In a special embodiment, it is proposed that the eccentric valve lever is integrated in the piston valve which makes the activating pin inexpensive to produce. The activating pin works independently of the piston control fit.
A third embodiment comprises a similar combination to the one described in the second embodiment, except here the activating pin has a center drilling. It is appropriate if the center drilling at each end expands gradually by a circular cross section and has an angle xcex3 or xcex4, respectively, with the center axis of the activating pin and each angle is larger than 0xc2x0 and smaller than 20xc2x0 (usually in the interval between 6xc2x0 and 12xc2x0). In an appropriate embodiment, the top of the piston of the activating pin forms a valve seat for the valve (304). This results in a large opening area created by a small movement of the eccentric valve lever. In a special embodiment it is suggested that the eccentric valve pin is loose in the piston and a stop device is used to stop its movement. The stop device is an integrated part of the piston valve and is resilient in relation to it. The piston valve rod has e.g. a xe2x80x9cflower-shapedxe2x80x9d cross section and the piston rod e.g. a circular cross section, resulting in channels (321). The activating pin is very reliable and inexpensive to produce. The air flow in the valve connector is approximately laminar which ensures low aerodynamic drag so that it is comfortable when pumping even with (low pressure) pumps without an integrated non-return valve. The improvement over the activating pin shown in FIG. 9 in PCT/DK96/00055 is considerable regarding reduction in pumping force and pumping time and is as good as e.g. the valve connector of FIGS. 5a, 5b, 6 and 7.
A fourth embodiment is an alternative to the third embodiment. As the piston valve is rotating at an angle xcex8 in relation to the top of the piston, if activated by the eccentric valve pin, the rotation is limited with a stop device. The cross section of the piston rod can have two main forms, according the specific formula each being xe2x80x9cflower-shapedxe2x80x9d with different parameters, both resulting in an approximately laminar flow. In a special embodiment, the radius r0 is smaller than the radius of the core of a Schrader valve while the air is flowing through the distals of the xe2x80x9cflower shapedxe2x80x9d cross section. The eccentric valve lever is similar to the loose type of FIG. 5d, with the difference being that the top is rounded off. The characteristics of this model are almost in accordance with those of the third embodiment.
In a fifth embodiment of the invention, the activating pin is designed as a piston with a piston rod that is slidable in the cylinder-shaped coupling house. The activating pin has a center drilling with an axially slidable valve in the center drilling that is kept closed by a spring where the center drilling of the activating pin has e.g. a xe2x80x9cflower-shapedxe2x80x9d cross section (FIG. 8.1) and the piston valve rod has a circular one resulting in a reliable control and efficient air passage. The center drilling at each end expands gradually by a circular cross section. The walls of the gradual expansions form an angle xcfx81 or xcfx86, respectively, between 0xc2x0 and 20xc2x0 (usually in the interval between 6xc2x0 and 12xc2x0). The wall of the gradual expansion by the piston part of the center drilling forms a valve seat for the seal face of the valve. The seal face of the valve is pressed into the correct position by a spring, e.g. an elastic band. In a special embodiment, the sealing surface is a small area with an angle xcexa8, in relation to the center axis, of approximately 90xc2x0-150xc2x0 (incl.) as seen in the flow direction of the air at flow from the side of the pressure source. This enables improved sealing. In a special embodiment, the valve is equipped with at least one fin or a similar device, which fits on the top of the edge of a Dunlop-Woods inner valve. It also fits either the top of the core of a Schrader valve, or the bridge of a Schrader valve without fitting the top of its core, as the activating pin does. In the last mentioned embodiment, the fin is equipped with a device perpendicular to the fin. Furthermore, the center drilling in the last-mentioned embodiment can also be designed in a way that provides a favorable flow in the area around the fin of the piston part. If e.g. combined with a pump with a built-in check-valve, the space between the connector and the check-valve need to have an airing or a similar solution. The activating pin is reliable, as it works independent of the piston rod fit and the tolerances of the pump valves. It is inexpensive to produce and it gives a low pump force, specifically with pumps without a check-valve. It works independent of piston control fit or pump valve tolerances.
In a sixth embodiment of the invention, the activating pin has a center axial drilling with a valve that is axially slidable in the drilling and is kept closed by means of a spring. The valve and the spring are made of one piece of deformable material. The axially slidable valve and the spring are partly formed by a conic section, with an apex angle (2xcex5), and partly formed by an approximately cylindrical section with a mainly circular cross section. The spring is attached to the piston part of the activating pin by means of a securing device. This is expedient if the wall of the center drilling in the activating pin is gradually expanded and has an angle xcex7 or xcexd, respectively, in relation to the center axis of the activating pin. Each angle is larger than 0xc2x0 and smaller than 20xc2x0 (usually in the interval between 6xc2x0 and 12xc2x0). The wall of the gradual expansion of the center drilling thus forms a valve seat for the seal face of the valve. The valve is pulled to the tightening position by the spring. In a special embodiment of the invention, the piston part is equipped with at least one fin or a similar device which fits on top of the core of a Schrader valve.
In another embodiment of the activating pin, the slidable valve has two cones resting upon each other. This turns the air flow around the valve and in the grooves into an approximately laminar flow. The piston valve rod and the piston rod define e.g. a cylindrical channel, while the rest of the piston rod has a xe2x80x9cflower-shapedxe2x80x9d cross section. The embodiment of the flow ensures low aerodynamic drag so that it is comfortable when pumping even with low pressure pumps without an integrated non-return valve. In addition, the invention is inexpensive. It works independently of piston control fit and pump valve tolerances. In a special embodiment, the sealing surface of the cones is a small area with an angle "xgr" in relation to the center axis of approximately 90xc2x0-150xc2x0 (incl.) with the center axis as seen in the flow direction of the air at flow from the side of the pressure source. This enables improved sealing. In the case of combining this embodiment with pumps with an built-in check-valve, the space between the connector and the check-valve needs to be equipped with airing or the like. Instead of air, (mixes of) gasses and/or liquids of any kind can activate and flow through and around the embodiments of the activating pin. The invention can be used in all types of valve connectors, where at least a Schrader valve or any valve with a spring operated core can be coupled, irrespective of the method of coupling or the amount of coupling holes in the connector. Further, the invention can be coupled to any pressure source irrespective of whether or not there is a securing means in the valve connector. Any possible combination of the embodiments shown in the specification fall into the scope of the present invention. The various embodiments described above are provided by way of illustration and should not be constructed to limit the invention. Those skilled in the art will readily recognize various modifications and changes which may be made to the present invention without strictly following the exemplary embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the present invention.